A multistage cluster random sampling strategy was used to select study participants from
urban and rural locations. First, clusters (smallest administrative units, known as kebeles in
Ethiopia) were selected using simple random sampling after obtaining the latest list from the
district administration. Secondly, households were selected within each cluster using the systematic
random sampling technique. Finally, one individual was selected out of eligible adults
in each household using simple random sampling. Details of the study population and sampling
procedures were previously described